diff --git a/daqingest/src/bin/daqingest.rs b/daqingest/src/bin/daqingest.rs
index 0084aac..acc52bd 100644
--- a/daqingest/src/bin/daqingest.rs
+++ b/daqingest/src/bin/daqingest.rs
@@ -59,8 +59,16 @@ async fn main_run_inner(opts: DaqIngestOpts) -> Result<(), Error> {
             };
             let scyconf = ScyllaIngestConfig::new([k.scylla_host], k.scylla_keyspace);
             match k.sub {
-                DbSub::RemoveOlder(j) => {
-                    info!("RemoveOlder  {:?}  {:?}", pgconf, scyconf);
+                DbSub::Data(u) => {
+                    use daqingest::opts::DbDataSub;
+                    match u.sub {
+                        DbDataSub::RemoveOlder(params) => {
+                            info!("RemoveOlder  {:?}  {:?}", pgconf, scyconf);
+                            daqingest::tools::remove_older(u.backend, params, &pgconf, &scyconf)
+                                .await
+                                .map_err(Error::from_string)?;
+                        }
+                    }
                 }
             }
         }
diff --git a/daqingest/src/opts.rs b/daqingest/src/opts.rs
index 9646cf2..3966f9c 100644
--- a/daqingest/src/opts.rs
+++ b/daqingest/src/opts.rs
@@ -102,8 +102,7 @@ pub struct Db {
     pub scylla_keyspace: String,
     #[arg(long)]
     pub pg_host: String,
-    #[arg(long)]
-    #[clap(default_value = "5432")]
+    #[arg(long, default_value = "5432")]
     pub pg_port: u16,
     #[arg(long)]
     pub pg_user: String,
@@ -117,11 +116,24 @@ pub struct Db {
 
 #[derive(Debug, clap::Parser)]
 pub enum DbSub {
+    Data(DbData),
+}
+
+#[derive(Debug, clap::Parser)]
+pub struct DbData {
+    #[arg(long)]
+    pub backend: String,
+    #[command(subcommand)]
+    pub sub: DbDataSub,
+}
+
+#[derive(Debug, clap::Parser)]
+pub enum DbDataSub {
     RemoveOlder(RemoveOlder),
 }
 
 #[derive(Debug, clap::Parser)]
 pub struct RemoveOlder {
     #[arg(long)]
-    date: String,
+    pub date: String,
 }
diff --git a/daqingest/src/tools.rs b/daqingest/src/tools.rs
index e69de29..cb1b3dd 100644
--- a/daqingest/src/tools.rs
+++ b/daqingest/src/tools.rs
@@ -0,0 +1,73 @@
+use crate::opts::RemoveOlder;
+use chrono::DateTime;
+use chrono::Utc;
+use dbpg::conn::PgClient;
+use err::thiserror;
+use err::ThisError;
+use futures_util::StreamExt;
+use log::*;
+use netpod::Database;
+use scywr::config::ScyllaIngestConfig;
+use scywr::scylla::transport::errors::QueryError;
+use scywr::scylla::transport::iterator::NextRowError;
+use scywr::session::ScySession;
+
+#[derive(Debug, ThisError)]
+pub enum Error {
+    PgConn(#[from] dbpg::err::Error),
+    Postgres(#[from] dbpg::postgres::Error),
+    ScyllaSession(#[from] scywr::session::Error),
+    ScyllaQuery(#[from] QueryError),
+    ScyllaNextRowError(#[from] NextRowError),
+    ParseError(String),
+}
+
+pub async fn remove_older(
+    backend: String,
+    params: RemoveOlder,
+    pgconf: &Database,
+    scyconf: &ScyllaIngestConfig,
+) -> Result<(), Error> {
+    let channel_regex = "^TEST:SLOW:SCALAR:.+:00000[0-9]$";
+    let date_cut: DateTime<Utc> = params
+        .date
+        .parse()
+        .map_err(|_| Error::ParseError(format!("can not parse {:?}", params.date)))?;
+    let epoch: DateTime<Utc> = "1970-01-01T00:00:00Z".parse().unwrap();
+    let dt_epoch = date_cut.signed_duration_since(epoch);
+    let ts_cut = dt_epoch.num_seconds() as u64 * 1000000000;
+    debug!("chosen date is  {:?}  {}", date_cut, ts_cut);
+    let (pg, _) = dbpg::conn::make_pg_client(pgconf).await?;
+    let scy = scywr::session::create_session(scyconf).await?;
+    let sql = concat!(
+        "select series, channel from series_by_channel",
+        " where facility = $1 and kind = 2 and channel ~ $2"
+    );
+    let rows = pg.query(sql, &[&backend, &channel_regex]).await?;
+    for row in rows {
+        let series: i64 = row.get(0);
+        let channel: String = row.get(1);
+        let series = series as u64;
+        debug!("care about  {}  {}", channel, series);
+        remove_older_series(series, ts_cut, &pg, &scy).await?;
+    }
+    Ok(())
+}
+
+async fn remove_older_series(series: u64, ts_cut: u64, _pg: &PgClient, scy: &ScySession) -> Result<(), Error> {
+    let it = scy
+        .query_iter(
+            "select ts_msp from ts_msp where series = ? and ts_msp < ?",
+            &(series as i64, ts_cut as i64),
+        )
+        .await?;
+    type RowType = (i64,);
+    let mut it = it.into_typed::<RowType>().take(10);
+    while let Some(e) = it.next().await {
+        let row = e?;
+        let ts_msp = row.0 as u64;
+        debug!("remove ts_msp {}", ts_msp);
+        // TODO must know scalar type and shape (at least scalar or wave) to select the correct scylla table
+    }
+    Ok(())
+}
diff --git a/scywr/src/lib.rs b/scywr/src/lib.rs
index 38b04f6..14cf810 100644
--- a/scywr/src/lib.rs
+++ b/scywr/src/lib.rs
@@ -13,3 +13,5 @@ pub mod schema;
 pub mod session;
 pub mod store;
 pub mod tools;
+
+pub use scylla;
diff --git a/scywr/src/tools.rs b/scywr/src/tools.rs
index 9a4eaeb..84a61ef 100644
--- a/scywr/src/tools.rs
+++ b/scywr/src/tools.rs
@@ -133,3 +133,13 @@ pub async fn fetch_events(backend: &str, channel: &str, scylla_conf: &ScyllaInge
     }
     Ok(())
 }
+
+/*
+select * from ts_msp where token(series) >= 1500000000000000000 and token(series) < 1600000000000000000 and ts_msp < 1709112680000000000 allow filtering;
+
+Can also simply:
+scan the channel postgres database.
+iterate over the series ids.
+fetch all msp lower than.
+delete them individually.
+*/